Dragline bucket trunnion



Dec. 3, 1963 P. v. LARSEN DRAGLINE BUCKET TRUNNION 3 Sheets-Sheet 1Filed Sept. 6, 1962 by V 9/2 L 11 a 2L) P. V- LARSEN DRAGLINE BUCKETTRUNNION Dec. 3, 1963 3 Sheets-Sheet 2 Filed Sept. 6, 1962 5 ,f w gUnited States Patent Ofi ice 3,llZ,57Z l e-dented Dec. 3, 1953 3,112,572DRAGLEIIE BUCKET TRUNNlGN Paul Vernon Larsen, Portland, Greg, assignorto Eseo Corporation, Portland, Greg, a corporation of Oregon Filed Sept.6, 1962, Ser. No. 221,792 6 Claims. ((31. 37l35) This invention relatesto a dragline bucket trunnion, and, more particularly, to a trunnioncharacterized by advantageous positionability for stabilizing the bucketduring hoisting.

The dragline bucket trunnions are fittings provided on the vertical sidewalls of the bucket to which the hoist chains are connected. Thetrunnion locations are calculated from the center of gravity of thebucket so as to carry the loaded bucket in the air tilted back at abouta angle and also to carry the bucket in a vertical position after it hasdumped the load, i.e., with the front of the bucket hanging down.

It has been difficult to calculate this exact center both vertically andhorizontally for different types, sizes and widths of buckets. Also, thecenter of gravity changes with the bucket loading. Buckets loaded withclay to the top of the bucket have a different carrying factor than ifthe clay were piled over the bucket as high as the spreader bar. Stillfurther, the center of gravity location would be different if the bucketwere loaded with large rocks having considerable void spaces. Yetfurther, an entirely different centroidal condition is met for a bucketdigging under water, where the angle of repose of the material at thefront of the bucket changes. It is diiiicult to hold the material in thebucket when loading under water, and it is not uncommon for gravel toload in a bucket on a straight line from the lip to the top of the backof the bucket, which requires still another trunnion location to balancethe bucket properly.

From the foregoing, it is seen that it would be especially desirable tohave a positionable trunnion, and, although attempts at this have beenmade in the past, they have een attended by considerable diiiiculty. Itis to be appreciated that the trunnion provides a critical connectionsubject to considerable strain when the loaded bucket is lifted.Therefore, it has not been found practical to make an easily adjustableor releasable connection. V/ith contemporary trunnions, it takes threemen 12 to 15 hours, or one man about three days, toremove the rivets andtrunnion, burn or drill new holes, and replace the trunnion in the newposition. Not only is this expensive, but, more importantly, it puts thebucket out of service during this time. Also, it is necessary to Weld upall of the old holes from the previous location. Further, because of thevariation in material and the new location of the trunnion, it must beassumed that it is possible to still have an incorrect location afterthe trunnion has been adjusted through the lengthy procedure justoutlined.

t is therefore an object of the instant invention to provide a noveltrunnion that overcomes the shortcomings of previously-employedtrunnions, i.e., being characterized by ready repositionability so as toaccommodate the bucket to a variety of loading conditions.

Another object is to provide a trunnion for a dragline bucketcharacterized by a high degree of stability in use and which isconstructed to resist a variety of stresses in addition to thosenormally encountered in hoisting.

Still another object is to provide a novel trunnionequipped bucketwherein the bucket is adapted for a variety of service conditions.

Other objects and advantages of the invention may be seen in the detailsof construction and operation set down in this specification.

The invention is described in conjunction with the accompanying drawing,in which:

FIG. 1 is a fragmentary rear elevational view of a dragline bucketequipped with the inventive trunnion;

FIG. 2 is a side elevational view of the bucket seen in FIG. 1;

FIG. 3 is an enlarged fragmentary side elevational view of the portionof the bucket equipped with inventive trunnion;

FIG. 4 is a sectional view, taken along the line 44 of FIG. 3;

FIG. 5 is a reduced size rear the sight line 55 of FIG. 4;

FIG. 6 is a view similar to FIG. 4 but of a modified form of trunnion;

FIG. 7 is a view similar to FIG. 5 but taken along the si ht line 7-7applied to FIG. 6; and

FIG. 8 is a fragmentary perspective view of the trunnion-equippedbucket.

in the illustration given, and with reference to FIGS. 1 and 2, theenvironment for the invention is seen to include a dragline bucketgenerally designated 10 which is made up of side walls 11 and 12, a rearend Wall 13, and a bottom wall 14. This provides an open top and openfront for the accumulation of gravel, rock, etc. by virtue of a draggingoperation initiated by a pulling force exerted on the drag chain 15. Thedrag chain 15 is secured by virtue of a hitch extension 16 to a hitchplate 17 on the forward side walls 11 and 12.

Pulling of the bucket by exerting a pulling force on the drag chain 15advances the bucket with its forward lip and teeth 1i biting into theground. Dumping of the bucket is achieved through a cable 19 reeved in ahoist socket 2t? and connected to the arch anchor 21.

Hoisting of the bucket is achieved through a cable 22 connected to ahoist socket wedge 23, and this in turn to the hoist chains 24. Thehoist chains 24 are maintained in spaced-apart fashion by a spreader bar25 with the lower end of the chains 24 being connected to a trunnz'onlink 26 connected to the trunnion generally desigated 27.

Referring now to FIGS. 3-5, the trunnion 27 is seen in enlarged form andis secured to a trunnion plate 28 provided as a reinrorcement for theside wall 12.

The trunnion is seen to include a unitary body made up of a circularplate-like portion 29 (see FIG. 5). One quadrant as generally designated34 in FIG. 3 is interrupted to provide a transversely thickened portiongenerally designated 31 in FIG. 4. The thickened portion 31 is equippedwith aligned openings 32 and 33 in which the trunnion pin 34 isreceived. The trunnion pin 34 is maintained in place by virtue of akeeper 35 extending through the head 34a of the pin and through alignedopenings in the enthickened portion 31. The enthickened portion 31 isclevis-like in nature and provides spaced-apart, pin-receiving arms 36and 37 carrying, respectively, the holes 32 and 33. The space betweenthe arms 36 and 37 receives the trunnion link 26.

The circular plate-like portion 29 is seen to include a plurality ofarcuately-disposed holes 38. Similarly-arranged holes 39 (see FIG. 4)are provided in the side wall 12 of the bucket it) for the receipt ofsecuring bolts 49. It will be appreciated that other securing means,such as rivets, may be employed. However, it will be seen that thetrunnion pin 34- is positioned eccentrically relative to the center ofthe bolt holes 38.

The enthickened portion 31 is seen to taper downwardly and inwardly asat 41 (see FIG. 4). and this is advantageous L1 maintaining the bearingof the trunnion against the reinforcing plate 28 so that the trunnionmounting plan view, taken along B :9 will not be knocked off by impactwith rocks while the bucket is being dragged.

Reference to FIG. 5 reveals that the bolt openings 33 are disposed aboutan arc of about 270-ieaving with out openings the quadrant providing thetrunnion pin support. However, the bucket side wall has openings over a360 arc. Also, the bearin face of the trunnion 27 is equipped with areinforcing web 4-2 extending along a a diameter bisecting the quadrant30.

On a 35 cubic yard bucket, the holes 38 are provided at 15 intervals,with the center of the pin 34 lying on the continuation of the peripheryof circular plate-like portion 29, being on a radius of 11%". Thisarrangement yields 105 of are as the full adjustment of the trunnion,and the maximum possible adjustment of the bucket provides dumping at 6/2 from the vertical.

In the operation of the device, the eccentric trunnion pin 34 ispositioned according to calculation to develop the proper lifting anddumping action. Normally, this is at 30 to the vertical, as shown inFIG. 3. Should this prove erroneous, the bolts are removed from thevarious openings 39 and 38 and the trunnion rotated to a new position,after which the bolts are reinstalled.

The size of the trunnion and the arcuate spacing of bolt holes may bevaried according to the size of the bucket. The modification seen inFIGS. 6 and 7 is for use with an 85 cubic yard bucket, and in thisinstallation, the openings are arcuately spaced by 18. Other spacings,of the order of 1020, depending upon the size of the bucket, may beadvantageously employed. I prefer, however, to limit the openings to the270 arc shown so as to have maximum metal in the important bearing areaunder the trunnion pin. In the case of larger buckets requiring largertrunnions, as seen in FIGS. 6 and 7,

the inventive trunnion 127 is equipped wtih a centering pin 143, whichextends through an opening 144 provided in the bucket side wall. Theintegrally cast pin 143 serves as a center to fit into the hole 144 sothat the trunnion may be rotated on the center when adjusting andassembling. The pin 143 also acts as a shear pin in assisting the rivetsor bolts to hold it tightly to the side of the bucket.

While, in the foregoing specification, a detailed description of anembodiment of the invention has been a set down for the purpose ofexplanation thereof, many variations in the details herein given may bemade by those skilled in the art without departing from the spirit andscope of the invention.

I claim:

1. In a dragline bucket a body having upstanding side walls, andconnective rear and bottom walls, a trunnion on each side wall forconnecting a hoist chain thereto, each trunnion comprising a unitarybody having a plurality of holes extending therethrough,

said holes being arcuately arranged, said body being equipped with apin-carrying portion eccentrically related to the center of the holearc, said side walls having a plurality of openings also arcuatelyarranged to register with said holes, and means extending through saidopenings and holes for releasably securing said trunnions to said sidewalls.

2. The structure of claim 1 in which each of said trunnions is equippedwith holes over about an arc of 270.

3. The structure of claim 1 in which said holes are spaced apart by anangle of about 10-20".

4. The structure of claim 1 in which said pin-carrying portion tapersinwardly and downwardly.

5. The structure of claim 4 in which said body is equipped with. anintegral pin centered relative to said arcuately arranged holes, each ofsaid side walls being apertured centrally relative to said openings,with said pin being iournaled therein.

6. In a dragline bucket, a body having upstanding side walls andconnective rear and bottom walls, a trunnion on each side wall forconnecting a hoist chain thereto, each trunnion comprising a unitary,generally circular body having one side bearing against the outside of abucket side wall, the opposite side of said body being tapered towardsaid one side to provide an enthickened portion oflset relative to thecenter of said circular body, aligned pin-carrying openings in saidenthickened portion for connection to a hoist chain, a plurality ofholes arcuately arranged about said center and extending through saidbody, said side walls having a plurality of openings also arcuatelyarranged to register with said holes, and means extending through saidside wall openings and holes for releasably securing said trunnions tosaid side walls.

References Gited in the file of this patent UNITED STATES PATENTS Re.19,683 Pollock Aug. 27, 1935 7 1,050,838 King Jan. 21, 1913 1,104,771Bjorge July 28, 1914 2,092,556 Page Sept. 7, 1937 2,909,352 Van BurenOct. 20, 1959

1. IN A DRAGLINE BUCKET, A BODY HAVING UPSTANDING SIDE WALLS, ANDCONNECTIVE REAR AND BOTTOM WALLS, A TRUNNION ON EACH SIDE WALL FORCONNECTING A HOIST CHAIN THERETO, EACH TRUNNION COMPRISING A UNITARYBODY HAVING A PLURALITY OF HOLES EXTENDING THERETHROUGH, SAID HOLESBEING ARCUATELY ARRANGED, SAID BODY BEING EQUIPPED WITH A PIN-CARRYINGPORTION ECCENTRICALLY RELATED TO THE CENTER OF THE HOLE ARC, SAID SIDEWALLS HAVING